JP4003670B2 - Intercom transfer device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to an interphone transfer apparatus for transferring call voice with an interphone handset to a call terminal outside the home through a public telephone line network.
[0002]
[Prior art]
  2. Description of the Related Art Conventionally, an interphone system having an interphone slave installed outside the home and an interphone master installed in the home and connected to the interphone slave via a telephone line is provided. A conventional example of this type of intercom system is shown in FIG. 13 (see Patent Document 1).
[0003]
  The interphone master M ′ includes a microphone 1, a speaker 2, a two-wire / four-wire converter 5, a microphone amplifier G1, a line output amplifier G2 that amplifies a transmission signal to a line (two-wire transmission path), and a line from the line. A line input amplifier G3 for amplifying a received signal, a speaker amplifier G4, a transmission volume adjustment amplifier G5, a reception volume adjustment amplifier G6, and first and second echo cancellers 30A and 30B. The interphone slave unit S includes a microphone 1 ', a speaker 2', a two-wire / four-wire converter 5 ', a microphone amplifier G1', and a speaker amplifier G4 '.
[0004]
  The first echo canceler 30A has a conventionally known configuration including an adaptive filter 31A and a subtractor 32A, and a feedback path (acoustic echo path) H formed by acoustic coupling between the speaker 2 and the microphone 1._ACIs adaptively identified by the adaptive filter 31A, and an echo component (acoustic echo) estimated from the reference signal (input signal to the speaker amplifier G4) is output from the microphone amplifier G1 by the subtractor 32A (point in FIG. 13). By subtracting from (A signal), the echo component is canceled and eliminated. The second echo canceller 30B also has a conventionally well-known configuration including an adaptive filter 31B and a subtractor 32B. The reflection and intercom elements due to impedance mismatch between the two-wire / four-wire converter 5 and the transmission path. Feedback path (line echo path) H formed by the acoustic coupling between the speaker 2 'and the microphone 1' in the instrument S_LINIs adaptively identified by the adaptive filter 31B, and the echo component (line echo) estimated from the reference signal (input signal to the line output amplifier G2, that is, transmission signal) is received by the subtractor 32B (see FIG. 13). By subtracting it from the signal at point C), the echo component is canceled and eliminated.
[0005]
  Thus, the first and second echo cancellers 30A and 30B return the feedback path H._ACAnd H_LINThis cancels the echo component and breaks the closed loop, so that unpleasant echoes and howling can be suppressed. Further, according to the above-described conventional example, components other than the echo included in the output signal of the microphone amplifier G1, that is, the voice signal uttered by the caller to the interphone base unit M ′ and the noise around the interphone base unit M ′. Can be transmitted to the intercom handset S side without any loss. Similarly, components other than the echo included in the received signal, that is, the voice signal and interphone spoken by the caller to the interphone handset S can be transmitted. The noise around the handset S can be transmitted to the interphone base unit M ′ without any loss. Therefore, two-way simultaneous calls can be realized.
[0006]
[Patent Document 1]
  JP 2002-359580 A (paragraph 0004-paragraph 0006, FIG. 24)
[0007]
[Problems to be solved by the invention]
  By the way, in the past, there was provided an interphone master unit with an answering machine function to record a visitor's message, but if it was an urgent requirement, recording a message would not make much sense There is no. In addition, if the visitor is a dangerous person such as a thief, it will be bothered to inform that the visitor is away, which is inconvenient in terms of security.
[0008]
  The present invention has been made in view of the above circumstances, and the purpose of the present invention is to enable a home away from home to respond to a visitor through an intercom cordless handset even when he / she is away. It is to provide an intercom transfer device that improves the above.
[0009]
[Means for Solving the Problems]
  In order to achieve the above object, an invention of claim 1 provides an intercom system having an intercom handset installed outside the home and an interphone base set installed in the home and connected to the intercom handset through a telephone line. Call processing for transferring calls between the intercom handset and the outside call terminal in a bidirectional manner, and a transfer means for transferring call voice with the interphone handset to the call terminal outside the house through the public telephone line network. Call processing means for performing communication, a first 2-wire to 4-wire conversion means provided between the call line and the call processing means, and a second 2-wire to 4-wire conversion provided between the transfer means and the call processing means. With meansThe call processing means includes a first echo canceler for canceling echo generated by acoustic coupling at a telephone terminal outside the home or signal wraparound at the second 2-wire to 4-wire conversion means, and acoustic coupling or A second echo canceller for canceling echo generated by the signal wraparound in the one 2-wire / four-wire conversion means, and a speech sound provided on the signal path of the speech signal sandwiched between the first and second echo cancellers A volume adjustment amplifying means and a voice switch provided between the first and second echo cancellers, and reducing a loop gain formed by each echo path to suppress howling, First loss insertion means for inserting a loss into the signal path of the call signal transmitted from the telephone terminal outside the home to the interphone handset, and the signal path of the call signal transmitted from the interphone handset to the telephone terminal outside the home A second loss insertion means for inserting a loss into the first loss insertion means, and an insertion loss amount control means for controlling the amount of loss inserted from the first and second loss insertion means. The first feedback gain in the first feedback path that returns from the output point of the loss insertion means to the input point of the first loss insertion means via the feedback path on the side of the telephone terminal outside the home is estimated, Loss insertion means Estimating the second feedback gain in the second feedback path that feeds back from the power point to the input point of the second loss insertion means via the feedback path on the intercom handset side, and estimates of the first and second feedback gains A total loss amount calculation unit that calculates the sum of the loss amounts to be inserted into the closed loop based on the An insertion loss amount distribution processing unit that determines the distribution of the insertion loss amounts of the first and second loss insertion means, and the total loss amount calculation unit is based on the estimated values of the first and second feedback gains. There are two operation modes: an update mode that calculates and adaptively updates the total amount of loss to be inserted into the closed loop, and a fixed mode that fixes the total loss to a predetermined initial value. First and second echo cans from the start of a call with the terminal In the period until the signal sufficiently converges, the first switch is operated in the fixed mode, and in the period after the first and second echo cancellers are sufficiently converged, the operation is performed in the update mode. And a third loss insertion means provided at a subsequent stage of at least one of the second loss insertion means to insert a loss into the signal path, and a voice switch in the signal path provided with the third loss insertion means. Instantaneous power estimation means for estimating the instantaneous power of the input signal, and when the estimated value of instantaneous power by the instantaneous power estimation means continues for a predetermined time or more and falls below a threshold value, The call processing means includes control means for inserting lossIt is characterized by that.
[0010]
  The invention of claim 2In order to achieve the above object, a public telephone line network is used for an interphone system having an intercom handset installed outside the home and an interphone main unit installed in the house and connected to the intercom handset via a telephone line. A transfer means for transferring call voice with the intercom handset to a call terminal outside the home through, a call processing means for performing a call processing for making a two-way call between the interphone handset and the call terminal outside the home, A first two-wire / four-wire conversion means provided between the call line and the call processing means; and a second two-wire / four-wire conversion means provided between the transfer means and the call processing means. The means includes a first feedback path caused by acoustic coupling in a telephone terminal outside the home or signal wraparound in the second 2-wire to 4-wire conversion means, and acoustic coupling in the intercom handset or the first The voice switch has a voice switch that suppresses howling by reducing the loop gain of the closed loop formed by the second feedback path generated by the signal wraparound in the line-to-line conversion means. A first loss insertion unit that inserts loss into the signal path of the call signal transmitted to the handset; and a second that inserts loss into the signal path of the call signal transmitted from the interphone handset to the call terminal outside the home. The first and second feedback gains that are fed back through the loss insertion unit and the first and second feedback paths are estimated and inserted into the closed loop based on the estimated values of the first and second feedback gains, respectively. Insertion loss amount control that calculates the sum of power loss amounts and determines the distribution of the insertion loss amounts of the first and second insertion loss units according to the call state estimated by monitoring the call signal and the total loss amount Department and A first background noise level estimation unit for estimating a background noise level on the side of a call terminal outside the home included in the call signal, and a second background noise level for estimating a background noise level on the intercom handset side included in the call signal Monitoring is performed by the estimation unit, the first bias mode setting amplification unit that amplifies the call signal from the remote call terminal monitored by the insertion loss amount control unit to the interphone handset, and the insertion loss amount control unit. A second bias mode setting amplification unit for amplifying a call signal from the intercom handset to the outside call terminal; a first feedback gain estimation unit for estimating a feedback gain of the first feedback path; and a second feedback A second feedback gain estimator for estimating a feedback gain of the path; first and second biased mode settings according to the first and second background noise levels and the estimated values of the first and second feedback gains; Each gain of amplifier A bias mode control unit that adjusts the second background noise level estimate value is sufficiently larger than the first background noise level estimate value and the first feedback gain. If the state in which the estimated value is smaller than the predetermined value continues for a certain time or longer, the gain of the first bias mode setting amplification unit is increased more than the gain of the second bias mode setting amplification unit. Is set to the first bias mode, the estimated value of the first background noise level is sufficiently larger than the estimated value of the second background noise level, and the estimated value of the second feedback gain is larger than the predetermined value. If the state of the lower value continues for a certain time or longer, the gain of the second bias mode setting amplification unit is increased more than the gain of the first bias mode setting amplification unit, and the voice switch is set to the second bias mode. Set and estimate the first background noise level If the state in which the difference between the estimated values of the second background noise level and the second background noise level is sufficiently large does not continue for a certain time or longer, the call processing is not performed by amplifying the call signal in the first and second bias mode setting amplification units. Set the instrument to neutral modeIt is characterized by that.
[0011]
  The invention of claim 3 is the invention of claim 1 or 2,A microphone and a speaker, and switching connection means for selectively switching and connecting the second two-wire / four-wire conversion means to the microphone, the speaker and the transfer means.It is characterized by that.
[0012]
  Claim4The invention of claim 1Any of ~ 3In the present invention, when an abnormality such as a fire or a gas leak is detected by a sensor installed in the house, a voice generating means for generating an alarm message or an alarm sound according to the content of the detected abnormality, a call processing means, Comprises a voice call processing circuit constituted by a single processor.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
  Before describing the embodiment of the present invention, a reference example having the same basic configuration as the embodiment of the present invention will be described below.
[0014]
  (Reference example1)
  BookReference exampleFIG. 1 shows a system configuration of an interphone system using the interphone transfer device M and a configuration of the interphone transfer device M.
[0015]
  An intercom handset B installed at a front door or the like outside the home and an interphone master unit A installed in the home are connected by two communication lines Ls. Then, the intercom master A and the interphone transfer device M installed in the house are connected by the two call lines Ls' and the control line Lc. A general telephone D installed in the house is connected to the interphone transfer apparatus M, and the interphone transfer apparatus M is connected to the public telephone line network N through a telephone line Lt wired in the house. Note that the telephone D can make and receive calls from the interphone transfer device M to the outside call terminal C such as a mobile phone via the public telephone line network N.
[0016]
  The interphone transfer device M includes a telephone interface unit 3 serving as a transfer means for transferring call voice with the intercom handset B to the outside call terminal C through the public telephone line network N, and the interphone handset B and the outboard call terminal C. A call processing unit 4 that performs a call process for making a two-way call, a first 2-wire / four-line conversion unit 5 provided between the call line Ls ′ and the call processing unit 4, and a telephone interface unit 3. And a second two-wire / four-wire converter 6 provided between the call processor 4 and the interphone transfer device M according to a control command received from the interphone master A via the control line Lc with the CPU as a main component. And a control unit 7 that performs overall control of the above.
[0017]
  Next, the configuration of the call processing unit 4 will be described with reference to FIG. However, the same reference numerals are given to the same components as those of the call processing unit in the intercom base unit M ′ of the conventional example, and the description thereof is omitted.
[0018]
  A voice switch 10 is provided between volume control amplifiers G5 and G6 provided on the signal path of the speech signal sandwiched between the first and second echo cancellers 30A and 30B. The voice switch 10 includes a first loss insertion unit 11 that inserts a loss into the signal path of a call signal transmitted from the out-of-home call terminal C to the intercom handset B, and a transmission from the intercom handset B to the out-of-home call terminal C. A second loss insertion unit 12 that inserts a loss into the signal path of the call signal to be transmitted, and an insertion loss amount control unit 13 that controls the amount of loss inserted from the first and second loss insertion units 11 and 12. To do.
[0019]
  The insertion loss amount control unit 13 performs a first feedback that returns from the output point Rout of the second loss insertion unit 12 to the input point Tin of the first loss insertion unit 11 via a feedback path on the outside call terminal C side. The first feedback gain α in the path H1 is estimated, and the feedback is made from the output point Tout of the first loss insertion unit 11 to the input point Rin of the second loss insertion unit 12 through the feedback path on the intercom handset B side. The second feedback gain β in the second feedback path H2 is estimated, and the total amount of loss to be inserted into the closed loop is calculated based on the estimated values α ′ and β ′ of the first and second feedback gains α and β. The total loss amount calculation unit 14 to be calculated, the call state is estimated by monitoring the call signal, and the first and second loss insertion units 11 and 12 are determined according to the estimation result and the calculated value of the total loss amount calculation unit 14. Insertion loss amount distribution processing unit 15 for determining the distribution of each insertion loss amount The it has.
[0020]
  The total loss amount calculation unit 14 estimates the time average power of the input signal of the first loss insertion unit 11 in a short time using a rectifier / smoothing device, a low-pass filter, or the like. Is used to estimate the time average power of the output signal of the second loss insertion unit 12 in a short time, and the output signal of the first loss insertion unit 11 in the maximum delay time assumed in the first feedback path H1. Is obtained by dividing the estimated value of the time average power of the input signal of the second loss insertion unit 12 by this minimum value and the estimated value α ′ of the first feedback gain. At the same time, the time average power of the input signal of the first loss insertion unit 11 in a short time is estimated using a rectifier / smoothing device, a low-pass filter, etc. 1 loss insertion part 11 Estimating the time average power of the signal in a short time, obtaining the minimum value of the estimated value of the time average power of the output signal of the second loss insertion unit 12 at the maximum delay time assumed in the second feedback path H2, A value obtained by dividing the estimated value of the time average power of the input signal of the first loss insertion unit 11 by this minimum value is defined as a second feedback gain estimated value β ′. Then, the total loss amount calculation unit 14 calculates a total loss amount necessary for obtaining a desired gain margin from the estimated values α ′ and β ′ of the first and second feedback gains α and β, and calculates the value. The data is output to the insertion loss amount distribution processing unit 15.
[0021]
  The insertion loss amount distribution processing unit 15 monitors the input / output signals of the first and second loss insertion units 11 and 12, and determines the call state (for example, from the outside call terminal C, based on the magnitude relationship between the power levels of these signals). And the total loss amount is distributed at a rate corresponding to the determined call state and inserted into each signal path from the first and second loss insertion units 11 and 12. .
[0022]
  Next bookReference exampleThe operation of the intercom system will be described. First, the interphone master unit A is set to the normal mode when the housekeeper is at home. In this state, when a visitor operates a call button (not shown) of the intercom handset B, the interphone base unit A detects a call signal transmitted from the interphone handset B through the communication line Ls, and generates a ring tone from the speaker. Let it ring. Then, if the housekeeper operates the response button of the interphone master unit A in response to the ringing tone, a call can be made between the interphone master unit A and the interphone slave unit B. Note that when the interphone master A is set to the normal mode, a call is performed only between the interphone master A and the interphone slave unit B as described above, and the interphone transfer device M does not function at all.
[0023]
  On the other hand, in the intercom master A, when a transfer setting button (not shown) is operated, the transfer mode is set. When the call signal from the intercom handset B is detected while the transfer mode is set, the interphone master A transmits a transfer command to the interphone transfer device M via the control line Lc. The control unit 7 of the interphone transfer apparatus M that has received this transfer command is a telephone number of the transfer destination stored in the memory in advance (for example, a mobile phone carried by a housekeeper who has gone out or installed at the place where the housekeeper is out. The telephone interface unit 3 makes a call to the telephone number of the telephone set. Then, the transfer destination out-of-home call terminal (such as the above-mentioned mobile phone or telephone) C responds, and the line is closed between the intercom transfer device M and the out-of-home call terminal C via the public telephone line network N. Thereafter, the control unit 7 activates the call processing unit 4 and calls between the intercom handset B and the outside call terminal C via the interphone base unit A and the interphone transfer device M (hereinafter referred to as “transfer call”). ) Becomes possible.
[0024]
  In this way, by simply adding the intercom transfer device M according to the present invention to the existing intercom system, the call voice with the intercom handset B is transferred to an arbitrary outside call terminal C, and even when the user is away from home, Convenient as an interphone system, because it is possible for a householder to respond directly to a visitor through the intercom handset B, which can respond to urgent requirements and to make it appear that a thief or other dangerous person is at home. Improve security and security.
[0025]
  In the conventional example, the adaptive filters 31A and 31B of the first and second echo cancellers 30A and 30B normally require a learning time of several seconds to identify the impulse responses of the feedback paths H1 and H2. In other words, the feedback paths H1 and H2 cannot be cut off by the first and second echo cancellers 30A and 30B for a few seconds immediately after the start of the call, and a closed loop is formed in the call system. In such a state, the voice uttered by the caller can be heard by the caller himself as an echo, causing discomfort. Also, howling occurs if the gain of the amplifier is large. Therefore, in order to prevent howling even in a state where the echo cancellers 30A and 30B immediately after the start of the conversation have not converged (learning state for identifying the impulse response), the round-trip gain of the closed loop should not exceed 1 time. It is necessary to design the gain of each amplifier. This clearly imposes a restriction on the call volume.
[0026]
  The above is based on the premise that the coefficients of the adaptive filters 31A and 31B of the first and second echo cancellers 30A and 30B are all reset to 0 at the start of a call. On the other hand, a method of giving initial values of coefficients to the adaptive filters 31A and 31B in advance is also conceivable. However, since the characteristics of the feedback paths H1 and H2 to be identified by the adaptive filters 31A and 31B differ depending on the installation environment, It is possible that the cancellation effect of the feedback paths H1 and H2 cannot be obtained at all with the set initial value. Therefore, even in such a system, it is unavoidable that the call volume is restricted.
[0027]
  So bookReference exampleIn the interphone transfer apparatus M, the total loss amount calculation unit 14 of the insertion loss amount control unit 13 is to be inserted into the closed loop based on the estimated values α ′ and β ′ of the feedback gains α and β as described above. The first and second echo cancellers 30A from the start of the transfer call have two operation modes: an update mode in which the total amount is calculated and adaptively updated, and a fixed mode in which the total loss is fixed to a predetermined initial value. , 30B operate in a fixed mode during a period until it sufficiently converges, and operate in an update mode during a period after the first and second echo cancellers 30A, 30B sufficiently converge. That is, in the total loss calculation unit 14, the estimated values α ′ and β ′ of the first feedback gain α and the second feedback gain β are both predetermined for a predetermined time (several hundred milliseconds) from the start of the transfer call. The first and second echo cancellers 30A and 30B have sufficiently converged when the threshold value ε (for example, a value 10 dB to 15 dB smaller than the estimated values α ′ and β ′ at the start of the transfer call) is below It is assumed that the operation is performed in a fixed mode in which the total loss is fixed to the initial value before the time point, and in the update mode in which the total loss is adaptively updated based on the estimated values α ′ and β ′ after the time point Switch the operation mode. Note that the initial value of the total loss amount in the fixed mode is set to a value sufficiently larger than the total loss amount updated as needed in the update mode.
[0028]
  Thus, when the first and second echo cancellers 30A and 30B immediately after the start of the transfer call are not sufficiently converged, a sufficiently large value is set by the total loss calculating unit 14 operating in the fixed mode. Therefore, a stable half-duplex call can be realized by suppressing occurrence of unpleasant echoes and howling. Further, when the first and second echo cancellers 30A and 30B have sufficiently converged after a lapse of time from the start of the transfer call, the operation mode of the total loss calculation unit 14 is switched from the fixed mode to the update mode. Since the total loss amount inserted into the closed loop is reduced to a value sufficiently lower than the initial value, two-way simultaneous calls can be realized. In addition, by setting the initial value of the total loss amount to an appropriate value, the closed loop loop gain is reduced in order to prevent howling in the state where the first and second echo cancellers 30A and 30B have not converged immediately after the start of the call. The restriction of designing the gain of each amplifier so as not to exceed 1 time is eliminated.
[0029]
  Next, a specific operation of the total loss amount calculation unit 14 in the update mode will be described with reference to the flowchart of FIG.
[0030]
  The total loss amount calculation unit 14 executes the estimation processing of the first and second feedback gains α and β at a predetermined sampling period from the time point when the fixed mode is changed to the update mode (t = t1), and the estimated value α ′ (n) and β ′ (n) are calculated (step 1), and the gain margin MG of the closed loop is determined from the product of these two estimated values α ′ (n) and β ′ (n) and the gain margin MG. The total loss desired value Lr (n) required for maintaining [dB] is calculated by the following equation (step 2).
[0031]
  Lr (n) = 20 log | α ′ (n) · β ′ (n) | + MG [dB]
Note that α ′ (n), β ′ (n), and Lr (n) indicate the estimated feedback gain value and the desired total loss amount calculated by the nth sampling from the update mode transition point, respectively. Further, the total loss amount calculation unit 14 calculates the n-th total loss amount desired value Lr (n) calculated from the above formula and the previous (n−1) th total loss amount Lt (n−1), that is, the previous process. When the desired total loss amount Lr (n) calculated this time is larger than the total loss amount determined and actually inserted, a slight increase amount Δi [dB in the previous total loss amount Lt (n−1). ] Is set as the current total loss Lt (n) = Lt (n−1) + Δi (steps 3 and 4), and the total calculated this time with respect to the previous total loss Lt (n−1). When the loss desired value Lr (n) is small, the current total loss Lt (n) = Lt (n) is obtained by subtracting a slight decrease Δd [dB] from the previous total loss Lt (n−1). −1) −Δd (steps 5 and 6).
[0032]
  In this way, by suppressing the increase / decrease in the total loss amount by the total loss amount calculation unit 14 to a small value of Δi or Δd, the first and second echo cancellers 30A and 30B are set to converge just as the transfer call starts. Since the coefficients are actively updated, a sense of incongruity in hearing can be eliminated even in a state where the first and second feedback gains α and β change greatly.
[0033]
  (Reference example2)
  BookReference exampleFIG. 4 shows a system configuration of an intercom system using the interphone transfer apparatus. BookReference exampleIs the interphone base unit A configured as an interphone transfer device, and the basic configuration isReference example1 and common. Therefore,Reference exampleConstituent elements common to 1 are denoted by the same reference numerals, and description thereof is omitted as appropriate.
[0034]
  Interphone main unit A includes a microphone 1 and a speaker 2, a telephone interface unit 3 as a transfer means for transferring a call with the intercom handset B to an out-of-home call terminal C through a public telephone line network N, an interphone handset B and a home A call processing unit 4 that performs a call process for making a two-way call with the outside call terminal C, and a first two-wire / four-line conversion unit 5 provided between the call line Ls and the call processing unit 4; The second 2-wire / four-wire conversion unit 6 provided between the telephone interface unit 3 and the call processing unit 4, and the call processing unit 4 are connected to the microphone 1 and the speaker 2 and the second 2-wire / four-line conversion unit 6. Are provided with a switching connection unit 8 that selectively switches and connects, and a control unit 7 that performs overall control of the intercom master unit A.
[0035]
  The control unit 7 includes a CPU as a main component, detects a call signal transmitted through the communication line Ls when the call button is operated by the intercom handset B, sounds a ringing sound from the speaker 2, and the housekeeper makes a response button (Not shown) operates the call processing unit 4 to start a call with the intercom handset B, and controls the switching connection unit 8 to control the call processing unit 4 with the microphone 1 and the speaker 2 and the second. The function of selectively switching connection to the 2-wire to 4-wire conversion unit 6 and the transfer stored in the memory when the call signal from the intercom handset B is detected when the transfer mode is set as will be described later The telephone interface unit 3 has a function of making a call to the previous telephone number. The switching connection unit 8 switches between the normal mode in which the call processing unit 4 is connected to the microphone 1 and the speaker 2 and the transfer mode in which the call processing unit 4 is connected to the second 2-wire / four-line conversion unit 6. This is performed by the control unit 7 when a transfer setting button (not shown) is operated.
[0036]
  As shown in FIG.Reference example1 except that the microphone 1 and the speaker 2 are connected between the amplifiers G1 and G4 and the second two-wire / four-wire conversion unit 6 via the switching connection unit 8.
[0037]
  Next bookReference exampleThe basic operation of the intercom base unit A will be described. First, when the housekeeper is at home, the normal mode is set, and the control unit 7 controls the switching connection unit 8 to connect the call processing unit 4 to the microphone 1 and the speaker 2. When the visitor operates the call button of the intercom handset B in this state, the control unit 7 detects a call signal transmitted from the intercom handset B through the call line Ls and causes the speaker 2 to ring. Then, if the housekeeper operates the response button of the interphone master A in response to the ringing sound, the control unit 7 activates the call processing unit 4 to start a call with the interphone slave unit B.
[0038]
  On the other hand, when a transfer setting button (not shown) of the interphone master unit A is operated, the control unit 7 controls the switching connection unit 8 to change the call processing unit 4 to the second 2-wire-4 wire conversion unit 6. Connected and set to transfer mode. When the call signal from the intercom handset B is detected when the transfer mode is set, the control unit 7 causes the telephone number of the transfer destination stored in the memory in advance (for example, the housekeeper who has gone out carries it) The telephone interface unit 3 makes a call to a mobile phone or a telephone number of a telephone set installed outside the home. Then, the call destination out-of-home call terminal (such as the above-mentioned mobile phone or telephone) C responds and the line is closed between the intercom base unit A and the out-of-home call terminal C through the public telephone line network N. Thereafter, the control unit 7 activates the call processing unit 4 to enable a transfer call between the intercom handset B and the out-of-home call terminal C via the interphone base unit A.
[0039]
  Book like thisReference exampleThen, since the interphone transfer device is integrated into the interphone master unit A,Reference exampleCompared with the case where the interphone transfer device M is configured separately from the interphone base unit A as in FIG. 1, there are advantages that the system configuration is simplified, a space can be saved, and the degree of freedom of installation location is increased.
[0040]
  (Embodiment1)
  FIG. 6 is a block diagram showing the configuration of the call processing unit 4 in the interphone transfer apparatus of this embodiment. However, the configuration of the call processing unit 4 in this embodiment is as follows.Reference example1 is basically the same as 1, the same components are denoted by the same reference numerals, and description thereof is omitted.
[0041]
  Reference example1, the operation mode of the total loss calculation unit 14 shifts to the update mode, and in the silent state when the total loss amount in the voice switch 10 is low, the first or second feedback path H1, H2 When the characteristics fluctuate, learning of the adaptive filters 31A and 31B does not proceed because the level of the reference signal for the first and second echo cancellers 30A and 30B is low. As a result, the echo suppression characteristics of the echo cancellers 30A and 30B deteriorate. Therefore, there is a possibility that howling occurs when the round-trip gain of the closed loop of the telephone system exceeds 1 time.
[0042]
  Therefore, in the present embodiment, as shown in FIG. 6, a third loss insertion unit 20 provided after the first loss insertion unit 11 included in the voice switch 10 to insert loss into the signal path, The instantaneous power estimation unit 21 for estimating the instantaneous power of the input signal to the voice switch 10 in the signal path provided with the loss insertion unit 20 and the instantaneous power estimation value by the instantaneous power estimation unit 21 continue for a predetermined time or more. The call processing unit 4 is provided with a loss control unit 22 for inserting a predetermined amount of loss from the third loss insertion unit 20 when the threshold value is below the threshold value.
[0043]
  The third loss insertion unit 20 is an attenuator (attenuator) with a variable loss amount, and the loss control unit 22 selects the insertion loss amount between 0 [dB] and L [dB] (L> 0). Can be switched automatically.
[0044]
  The loss control unit 22 compares the instantaneous power estimation value Pti of the transmission signal sequentially input from the instantaneous power estimation unit 21 with the threshold value Pc, and the instantaneous power estimation value Pti is equal to or less than the threshold value Pc as shown in FIG. Whether or not the situation where (Pti ≦ Pc) continues for a predetermined time Te (several hundred ms) or more is constantly monitored, and when the above situation continues for a predetermined time Te or longer, the insertion of the third loss insertion unit 20 When the loss amount is switched from 0 [dB] to L [dB] and the instantaneous power estimation value Pti exceeds the threshold value Pc after switching, the insertion loss amount of the third loss insertion unit 20 is changed from L [dB]. Switch to 0 [dB]. In FIG. 7, the gain of the third loss insertion unit 20 is plotted on the vertical axis.
[0045]
  That is, the loss control unit 22 determines that the instantaneous power estimation value Pti of the call signal from the out-of-home call terminal C to the interphone handset B is equal to or less than the threshold value Pc, and the operation of the total loss calculation unit 14 is determined. After the mode is switched to the update mode, the first feedback gain α is obtained by inserting a loss (L [dB]) in the signal path on the transmission side when the silent state continues for a while (predetermined time Te). Alternatively, even when the second feedback gain β fluctuates, the round-trip gain of the closed loop of the speech system does not exceed 1 time, and howling can be prevented. Here, the loss control unit 22 controls the third loss insertion unit 20 to cause a loss in the signal path only when the total loss calculated by the total loss calculation unit 14 of the voice switch 10 is smaller than a predetermined value. If an excessive loss is inserted in the signal path, it is possible to suppress the sense of disconnection at the beginning, during and at the end of the speech. In addition, a rewritable nonvolatile memory (for example, EEPROM) that stores a threshold value Pc with respect to the instantaneous power estimated value Pti, a predetermined time Te, and a predetermined amount L [dB] of the insertion loss amount is provided, and the loss control unit 22 is provided. It is desirable to read out parameters such as the threshold value Pc from the memory (not shown) and perform the above-described control operation. In this way, it is possible to easily change parameters such as the threshold value Pc for the instantaneous power estimated value Pti from the outside, and it is possible to flexibly deal with various situations in the telephone system.
[0046]
  Note that a third loss insertion unit that is provided at the subsequent stage (output side) of the second loss insertion unit 12 included in the voice switch 10 and that inserts loss into the signal path, and an input point of the second loss insertion unit 12 The instantaneous power estimation unit for estimating the instantaneous power of the Rin signal (the communication signal from the intercom handset B to the remote call terminal C), and the estimated value of the instantaneous power by the instantaneous power estimation unit continues for a predetermined time or more. Instead of the third loss insertion unit 20, the instantaneous power estimation unit 21 and the loss control unit 22; It does not matter as a structure provided together. That is, even when these are provided, it is possible to prevent the occurrence of howling when the silent state continues for a while as described above, and when both are provided, it is possible to more reliably prevent the occurrence of howling. There is.
[0047]
  AlsoReference example8, the microphone 1 and the speaker 2 are connected between the amplifiers G1 and G4 and the second two-wire / four-wire conversion unit 6 via the switching connection unit 8 as shown in FIG. May be configured as the intercom base unit A.
[0048]
  (Embodiment2)
  FIG. 9 is a block diagram showing the configuration of the call processing unit 4 in the interphone transfer apparatus of this embodiment. However, the configuration of the call processing unit 4 in this embodiment is as follows.Reference example1 is basically the same as 1, the same components are denoted by the same reference numerals, and description thereof is omitted.
[0049]
  In the present embodiment, the first background noise level estimation unit 23 that estimates the background noise level on the outside call terminal C side included in the call signal and the background noise level on the intercom handset B side included in the call signal are estimated. A second background noise level estimator 24 and a first bias mode setting amplifying unit 25 for amplifying a call signal from the remote call terminal C monitored by the insertion loss control unit 13 to the intercom handset B. A second bias mode setting amplification unit 26 that amplifies a call signal from the intercom handset B monitored by the insertion loss amount control unit 13 to the outside call terminal C, and feedback of the first feedback path H1. A first feedback gain estimator 27 for estimating the gain α, a second feedback gain estimator 28 for estimating the feedback gain β of the second feedback path H2, the first and second background noise levels and the first And estimated values of the second feedback gains α and β | α The call processing unit 4 includes a weighting mode control unit 29 that adjusts the gains of the first and second weighting mode setting amplification units 25 and 26 according to ′ | and | β ′ |.
[0050]
  The first and second background noise level estimators 23 and 24 are each realized by an integration circuit or a digital filter having a characteristic that the rise is gradual and the fall is steep, and the first background noise level estimator 23 estimates the background noise level that is steadily present in the call signal output from the volume adjustment amplifier G5 (the transmission signal viewed from the outside call terminal C), and the second background noise level estimation unit 24 determines the volume. The background noise level that is constantly present in the call signal (received signal viewed from the outside call terminal C) output from the adjustment amplifier G6 is estimated. The estimation processing of the feedback gains α and β in the first and second feedback gain estimation units 27 and 28 is the same as the estimation processing by the total loss amount calculation unit 14.
[0051]
  The bias mode control unit 29 estimates the first feedback gain α when the estimated value PFn of the second background noise level is sufficiently larger than the estimated value PNn of the first background noise level (PFn >> PNn). If the state where the value | α ′ | is smaller than the predetermined value α0 (| α ′ | <α0) continues for a certain time T1 [seconds] or longer, the gain of the first bias mode setting amplification unit 25 is set to G1. [DB] (G1> 0), the gain of the second bias mode setting amplification unit 26 is set to 0 [dB], so that the voice switch 10 is set to the first bias mode, and the first background noise level The estimated value PNn is a value sufficiently larger than the estimated value PFn of the second background noise level (PNn >> PFn), and the estimated value | β ′ | of the second feedback gain H2 is smaller than the predetermined value β0 ( | Β ′ | <β0) continues for a certain time T2 [seconds] or longer. For example, the gain of the second bias mode setting amplification unit 26 is set to G2 [dB] (G2> 0), and the gain of the first bias mode setting amplifier 25 is set to 0 [dB]. 2 and the state where the difference between the estimated value PNn of the first background noise level and the estimated value PFn of the second background noise level is sufficiently large does not continue for a certain time T1 or T2 or longer. The voice switch 10 is set to the neutral mode by not amplifying the call signal by the first and second bias mode setting amplification units 25 and 26, that is, by making each gain substantially zero.
[0052]
  Reference example1, when the difference between the ambient noise level on the intercom handset B side and the ambient noise level on the home call terminal C side is large, the insertion loss amount control unit 13 that monitors the call signal and estimates the call state In a situation where the ambient noise level on the intercom handset B side is high, it is always determined as a reception state as seen from the outside call terminal C, and in a situation where the ambient noise level on the home call terminal C side is high, it is always seen from the outside call terminal C. There is a case where a phenomenon of so-called voice switch 10 (a so-called fall of the voice switch 10) occurs that is determined to be a transmission state and is fixed to either the reception state or the transmission state regardless of the actual call state. .
[0053]
  On the other hand, in this embodiment, the bias mode control unit 29 calculates the first background noise level estimated value PNn on the home call terminal C side and the second background noise level estimated value PFn on the intercom handset B side. In comparison, when the estimated value PFn of the second background noise level is sufficiently larger, the call signal (transmission signal viewed from the outside call terminal C) monitored by the insertion loss amount control unit 13 is the first bias mode. By amplifying the gain G1 [dB] by the setting amplifier 25, the insertion loss amount control unit 13 is set to a state (first bias mode) that is easy to determine as the transmission state viewed from the outside-call terminal C, and conversely When the estimated value PNn of the first background noise level is sufficiently larger, the call signal monitored by the insertion loss amount control unit 13 (received signal as viewed from the out-of-home call terminal C) is the second bias mode setting amplification unit. 26 is gain G2 [dB] Insert by amplifying loss controller 13 is prevented from falling pieces of voice switch 10 so as to set the state easy to determine the listen state as seen from the out-of-house speaking terminal C (second overemphasis mode).
[0054]
  Here, when the bias mode control unit 29 switches between the first bias mode, the second bias mode, and the neutral mode based only on the comparison result of the estimated values PNn and PFn of the first and second background noise levels. For example, when the first feedback gain α is a large value to some extent, a phenomenon in which the receiving state is supposed to be set when viewed from the outside-call terminal C (receiving blocking), When the feedback gain β is a certain large value, there is a possibility that a phenomenon (transmission blocking) that does not become a transmission state although it is supposed to be in a transmission state when viewed from the outside call terminal C may occur. .
[0055]
  Therefore, in the present embodiment, the bias mode control unit 29 determines not only the level difference between the estimated values PNn and PFn of the first and second background noise levels but also the estimated values of the first and second feedback gains α and β. In consideration of | α ′ | and | β ′ |, the weighting mode control unit 29 sets the first weighting mode, the second weighting mode, and the neutral mode. That is, even when the second background noise level estimated value PFn is sufficiently larger than the first background noise level estimated value PNn for a predetermined time T1 or longer, the first feedback gain α estimated value | α When '| exceeds the predetermined value α0, the shift to the first bias mode is not performed, so that the voice switch 10 can be prevented from falling down without causing reception blocking. Further, even when a situation where the estimated value PNn of the first background noise level is sufficiently larger than the estimated value PFn of the second background noise level continues for a certain time T2 or longer, the estimated value | β ′ of the line-side feedback gain β When | exceeds a predetermined value β0, the shift to the reception bias mode is not performed, so that it is possible to prevent the voice switch 10 from falling down without causing transmission blocking.
[0056]
  Here, in order to prevent reception blocking and transmission blocking, | α ′ | + G1 <M1, | β ′ | + G2 <M2 (rewriting this, | α ′ | <M1-G1 = α0, | β The relationship of '| <M2-G2 = β0) must be established. That is, the predetermined values α0 and β0 correspond to the margins M1 and M2 for reception blocking and transmission blocking, the gain G1 of the first bias mode setting amplifier 25, and the gain G2 of the second bias mode setting amplifier 26. It is determined. The gain G1 of the first bias mode setting amplifier 25 and the gain G2 of the second bias mode setting amplifying unit 26 are assumed to be the background on the home call terminal C side and interphone handset B side assumed in the usage environment, respectively. A request from the interphone transfer device M as to whether the voice switch 10 is switched to the transmission state or the reception state when the voice level is uttered from the home call terminal C side and the interphone handset B side with respect to the noise level. Determined based on specifications.
[0057]
  In additionReference example10, the microphone 1 and the speaker 2 are connected between the amplifiers G1 and G4 and the second two-wire / four-wire conversion unit 6 via the switching connection unit 8 as shown in FIG. May be configured as the intercom base unit A.
[0058]
  (Embodiment3)
  Conventionally, it is connected to fire detectors that detect fires with smoke or heat, gas leak detectors that detect gas leaks, emergency call switches installed in bathrooms and toilets, etc. When an emergency call switch is operated, an interphone master unit (so-called house information board) is provided that is configured to cause an alarm message or an alarm sound corresponding to the content of an abnormality to be generated from a speaker. And even in an interphone system (housing information board system) having such a home information board as a base unit, the security can be improved by adding the interphone transfer apparatus M according to the present invention.
[0059]
  FIG. 11 is a block diagram showing an interphone transfer apparatus M of the present embodiment corresponding to the interphone system (house information panel system) as described above. However,Reference Examples 1 and 2 and Embodiments 1 and 2Constituent elements common with the same reference numerals are designated by the same reference numerals, and description thereof is omitted.
[0060]
  The interphone transfer apparatus M of the present embodiment isReference Examples 1 and 2 and Embodiments 1 and 2The voice call processing circuit 40 having the call processing unit 4 described in any of the above and the voice generation unit 41 that generates the warning message and the warning sound as described above is provided. Here, a call signal (a transmission signal viewed from the outside call terminal C) input from the second 2-wire / 4-wire conversion unit 6 to the voice call processing circuit 40 is amplified by the amplifier 42 and then A / D converted. The signal is converted from analog to digital by the unit 43 and input to the call processing unit 4, and various call processing (Reference Examples 1 and 2 and Embodiments 1 and 2Are processed by the voice switch 10 and the echo cancellers 30A and 30B described in the above, and are converted from digital to analog by the D / A converter 44 and then amplified by the amplifier 45. A call signal (received signal viewed from the outside call terminal C) input from the first 2-wire / four-wire conversion unit 5 to the voice call processing circuit 40 is amplified by the amplifier 46 and then A / D conversion unit 47. Thus, the signal is converted from analog to digital and input to the call processing unit 4, the call processing unit 4 performs the above-described call processing, and the D / A conversion unit 48 converts the signal from digital to analog and then amplifies it by the amplifier 49.
[0061]
  The sound generation unit 41 is an alarm sound generation unit (not shown) that generates a digital alarm sound by appropriately selecting from a plurality of alarm sounds prepared in advance, and is compressed and stored in an internal or external memory. And a voice message decompression unit (not shown) for generating a digital voice message by appropriately selecting, reading and decompressing a plurality of voice message data. The alarm sound is for notifying the resident of the occurrence of an abnormality such as a fire or gas leak, and the voice message is a message (alarm message) for notifying the abnormality. The sound signals of special sounds such as warning sounds and voice messages generated by the sound generation unit 41 are converted from digital to analog by the D / A conversion units 50 and 53, and then amplified by the amplifiers 51 and 54. The first or second 2-wire to 4-wire converter is time-division multiplexed with the call signal (transmitted signal and received signal) output from the call processing unit 4 by the first or second analog signal multiplexers 52 and 55. 5 and 6 are output.
[0062]
  Thus, the control unit 7 of the interphone transfer device M receives an alarm sound generated by the voice generation unit 41 when a fire detection signal transmitted from the fire detector or an emergency call signal transmitted from the emergency call switch is received. And a warning message are transmitted to the intercom handset B and transmitted from the telephone interface unit 3 to the outside call terminal C. For this reason, even when the user is out of the office, it is possible to listen to an alarm sound or an alarm message by the outside call terminal C, and the security can be further improved.
[0063]
  Here, in the present embodiment, the voice call processing circuit 30 is constituted by a single processor such as a digital signal processor (DSP), and the above-described call processing unit is controlled by controlling the DSP hardware with dedicated software. 4 and the voice generation unit 41 are realized. In this way, since the voice call processing circuit 30 constituted by a single processor (DSP) performs simultaneous call processing and voice generation processing, it is compared with the conventional example in which each processing is performed by combining a plurality of integrated circuits. This has the advantage that the manufacturing cost can be reduced by reducing the number of parts.
[0064]
  (Embodiment4)
  In the present embodiment, as shown in FIG.3It is configured as an interphone transfer device, and the basic configuration isReference example2 andEmbodiment 3And in common. Therefore,Reference example2 andEmbodiment 3Constituent elements common with the same reference numerals are given the same reference numerals, and description thereof will be omitted as appropriate.
[0065]
  As shown in FIG. 12, in the interphone base unit A, the microphone 1 and the speaker 2 are connected between the amplifier 42 and the first analog signal multiplexing unit 52 and the second two-wire / four-wire conversion unit 6 via the switching connection unit 8. Connected. Also, the monitor unit 56, which is composed of a CRT, a liquid crystal display, etc., displays the video imaged by the imaging camera of the intercom handset B, and the video signal transmitted from the intercom handset B via the call line Ls is signal-processed. The interphone base unit A includes a video display circuit 57 that displays video on the monitor unit 56 and a signal separation unit 58 that separates the audio signal multiplexed from the interphone slave unit B and transmitted from the video signal.
[0066]
  On the other hand, the intercom handset B in the present embodiment includes an imaging camera, and an audio signal is transmitted via a communication line Ls formed of a pair of pair lines by multiplexing an FM-modulated video signal with an audio signal to be transmitted in baseband. The video signal is transmitted to the intercom base unit A. However, since such an interphone slave unit B with a camera is well known in the art, a detailed description thereof will be omitted.
[0067]
  In the intercom base A, the multiplexed audio signal and video signal received by the first 2-wire / four-wire conversion unit 5 are separated by the signal separation unit 58, and the video signal demodulated by the video display circuit 57 is monitored. By outputting to the unit 56, the video imaged by the imaging camera of the intercom handset B is displayed on the screen of the monitor unit 56.
[0068]
  On the other hand, the voice generation unit 41, in addition to the alarm sound generation unit and the voice message decompression unit, appropriately selects from a plurality of ringing sounds prepared in advance and generates a ringing tone generation unit (not shown). And a melody sound decompression unit (not shown) for generating a digital melody sound by appropriately selecting, reading and decompressing a plurality of melody sound data compressed and stored in the memory. Note that the melody sound is used as a ringing tone.
[0069]
  The voice generation unit 41 is a specific sound generation unit that generates a specific sound as an excuse for stopping the call by letting the other party call or a specific sound expansion unit that expands the specific sound data compressed and stored in the memory. At least one of them. For example, when answering a call from the intercom handset B, the other party (calling party) was an uninvited visitor, such as a salesman, and would like to immediately stop the call and pick up the visitor. There is a case that the housekeeper wants. In such a case, you can create an excuse to stop the call by letting the other party hear a sound such as a telephone ringing tone or a child's cry (named "specific sound"). For example, "The phone is ringing now You can quickly cancel a call with a person you do not want to talk to, such as "Please pick up." Or "Please pick up because the child is crying.
[0070]
  Thus, the sound signal of the special sound such as a ringing tone, alarm sound or voice message generated by the voice generation unit 41 is output from the call processing unit 4 by the first or second analog signal multiplexing units 52 and 55. And the speech signal (transmitted signal and received signal) are time-division multiplexed and output to the speaker 2 or the first or second two-wire / four-wire converters 5 and 6. In addition, the operation of the intercom base unit A in the normal mode and the transfer mode isReference exampleThe description is omitted because it is common to 2.
[0071]
【The invention's effect】
  The invention of claim 1 is used in an intercom system having an intercom handset installed outside a home and an interphone master set installed in the home and connected to the intercom handset via a telephone line, and through a public telephone line network. A transfer means for transferring call voice with the intercom handset to the call terminal outside the house, a call processing means for performing a call process for making a two-way call between the interphone handset and the call terminal outside the house, A first two-wire / four-wire conversion means provided between the line and the call processing means, and a second two-wire / four-wire conversion means provided between the transfer means and the call processing means.The call processing means includes a first echo canceler for canceling echo generated by acoustic coupling at a telephone terminal outside the home or signal wraparound at the second 2-wire to 4-wire conversion means, and acoustic coupling or A second echo canceller that cancels echoes generated by signal wraparound in one 2-wire / four-wire conversion means, and a speech volume provided on a signal path of a speech signal sandwiched between the first and second echo cancellers An adjustment amplifying means; and a voice switch that is provided between the first and second echo cancellers and suppresses howling by reducing a loop gain of a closed loop formed by each echo path. A first loss insertion means for inserting a loss into a signal path of a call signal transmitted from a call terminal outside the home to the interphone handset; Second loss insertion means for inserting a loss into the signal path of a call signal transmitted from the home to the call terminal outside the house, and insertion loss amount control means for controlling the loss amount inserted from the first and second loss insertion means And the insertion loss amount control means returns the first feedback from the output point of the second loss insertion means to the input point of the first loss insertion means via the feedback path on the side of the telephone terminal outside the home. In the second feedback path for estimating the first feedback gain in the path and returning from the output point of the first loss insertion means to the input point of the second loss insertion means via the feedback path on the intercom handset side A total loss amount calculating unit that estimates a second feedback gain and calculates a sum of loss amounts to be inserted into the closed loop based on the estimated values of the first and second feedback gains; And the calculation result and the total loss calculation part An insertion loss amount distribution processing unit that determines the distribution of the respective insertion loss amounts of the first and second loss insertion means according to the value, and the total loss amount calculation unit has the first and second feedback gains. An interphone handset having two operation modes: an update mode for calculating and summing up the total amount of loss to be inserted into the closed loop based on the estimated value, and a fixed mode for fixing the total loss to a predetermined initial value. During the period from the start of a call between the telephone terminal and the outside call terminal until the first and second echo cancellers sufficiently converge, the first mode and the second echo canceller are sufficiently converged after the operation in the fixed mode. A third loss insertion means which operates in the update mode during the period and is provided at a subsequent stage of at least one of the first and second loss insertion means included in the voice switch and inserts a loss into the signal path; , Third loss insertion means Instantaneous power estimation means for estimating the instantaneous power of the input signal to the voice switch in the signal path provided, and when the instantaneous power estimation value by the instantaneous power estimation means continues for a predetermined time or more and falls below the threshold value The call processing means includes a control means for inserting a predetermined amount of loss from the third loss insertion means.By simply adding it to the existing intercom system, the voice of the call with the intercom handset can be transferred to any remote call terminal, allowing the housekeeper to respond directly to the visitor from the outside. In addition to being able to meet requirements, it is possible to make people feel at home for dangerous persons such as thieves, thus improving convenience and security as an intercom system. In addition, in a state where the first and second echo cancellers immediately after the start of the call have not converged, the total loss amount is fixed to a sufficiently large initial value by the total loss amount calculation unit operating in the fixed mode, which is uncomfortable. In a state where stable half-duplex communication can be realized by suppressing generation of echo and howling and the first and second echo cancellers are sufficiently converged, the total loss calculation unit operating in the update mode performs the total loss Since the amount is updated as needed, two-way simultaneous calls can be realized.In addition, by setting the initial value of the total loss to an appropriate value, there is no restriction on the amplification gain including the call volume adjustment amplification means, so that a sufficient call volume with no practical problem can be obtained. Thus, the amplification gain can be designed. In addition, after the operation mode of the total loss calculation unit is switched to the update mode, when the silent state continues for a while, the signal path on the transmitting side or the receiving side is viewed from the outside call terminal. Even if the echo suppression characteristic of the echo canceller deteriorates due to the fluctuation of the characteristic of the first or second feedback path by inserting the loss, the loop gain of the closed loop of the communication system does not exceed one time, and howling Can be prevented.
[0072]
  The invention of claim 2Used in an intercom system that has an intercom handset installed outside the home and an interphone base unit installed in the home and connected to the intercom handset via a telephone line. A transfer means for transferring call voice with the handset, a call processing means for performing a call processing for making a two-way call between the intercom handset and the outside call terminal, and between the call line and the call processing means. And a second 2-wire / four-wire conversion means provided between the transfer means and the call processing means, wherein the call processing means is a call terminal outside the home. In the first feedback path caused by the signal coupling in the acoustic coupling or in the second two-wire to four-wire converting means, and in the intercom handset or in the first two-wire to four-wire converting means A voice switch that suppresses howling by reducing a loop gain of the closed loop formed by the second feedback path generated by the sneaking of the signal, and the voice switch is a call transmitted from the telephone terminal outside the home to the interphone handset A first loss insertion unit that inserts loss into the signal path of the signal, a second loss insertion unit that inserts loss into the signal path of the call signal transmitted from the intercom handset to the call terminal outside the home, And the first and second feedback gains that are fed back through the second and second feedback paths, respectively, and the total amount of loss to be inserted into the closed loop is calculated based on the estimated values of the first and second feedback gains. An insertion loss amount control unit that determines the distribution of each insertion loss amount of the first and second insertion loss units according to the sum of the call state and loss amount estimated by monitoring the call signal, and included in the call signal Outside A first background noise level estimator for estimating the background noise level on the talk terminal side, a second background noise level estimator for estimating the background noise level on the intercom handset side included in the speech signal, and insertion loss control A first bias mode setting amplifying unit for amplifying a call signal from an out-of-home call terminal monitored by the communication unit to the intercom handset, and an out-of-home call terminal from the intercom handset monitored by the insertion loss amount control unit A second bias mode setting amplifying unit for amplifying a call signal to the first, a first feedback gain estimating unit for estimating a feedback gain of the first feedback path, and a first gain for estimating the feedback gain of the second feedback path. 2, the gains of the first and second bias mode setting amplification units are adjusted according to the first and second background noise levels and the estimated values of the first and second feedback gains. A bias mode control unit, and a bias mode The control unit is in a state where the estimated value of the second background noise level is sufficiently larger than the estimated value of the first background noise level and the estimated value of the first feedback gain is smaller than the predetermined value. Continues for a certain time or more, the gain of the first bias mode setting amplification unit is increased more than the gain of the second bias mode setting amplification unit to set the voice switch to the first bias mode, If the estimated value of the background noise level is sufficiently larger than the estimated value of the second background noise level and the estimated value of the second feedback gain is a value smaller than the predetermined value continues for a certain time or longer. The gain of the second bias mode setting amplification unit is set to be larger than the gain of the first bias mode setting amplification unit to set the voice switch to the second bias mode, and the estimated value of the first background noise level The difference in the estimated value of the second background noise level is large enough Condition to be have values set to the neutral mode communications unit by not amplifying the speech signals in the first and second unbalance mode setting amplification unit to be continued for a fixed time or moreIt is characterized byBy simply adding to the existing intercom system, the voice of the call with the intercom handset can be transferred to any outside call terminal, allowing the housekeeper to respond directly to the visitor from outside the office and respond to urgent requirements. At the same time, it can make a dangerous person such as a thief feel at home, improving convenience and security as an intercom system. In addition, in a state where the first and second echo cancellers immediately after the start of the call have not converged, the total loss amount is fixed to a sufficiently large initial value by the total loss amount calculation unit operating in the fixed mode, which is uncomfortable. In a state where stable half-duplex communication can be realized by suppressing generation of echo and howling and the first and second echo cancellers are sufficiently converged, the total loss calculation unit operating in the update mode performs the total loss Since the amount is updated as needed, two-way simultaneous calls can be realized. In addition to the difference in ambient noise level between the intercom handset side and the outside call terminal side, the first and second estimated feedback gains are also considered in the first. Therefore, the voice switch can be prevented from falling over without causing transmission blocking and reception blocking as viewed from the outside call terminal.
[0073]
  The invention of claim 3 is the invention of claim 1 or 2,A microphone and a speaker, and switching connection means for selectively switching and connecting the second two-wire / four-wire conversion means to the microphone, the speaker and the transfer means.It is characterized bySince the interphone transfer device can be configured as an interphone master unit, the system configuration is simplified, space can be saved, and the degree of freedom of the installation location is increased as compared to the case where the interphone master unit is configured separately.
[0074]
  Claim4The invention of claim 1Any of ~ 3In the present invention, when an abnormality such as a fire or a gas leak is detected by a sensor installed in the house, a voice generating means for generating an alarm message or an alarm sound according to the content of the detected abnormality, a call processing means, Is provided with a voice call processing circuit constituted by a single processor, and a plurality of integrated circuits are provided to perform call processing and voice generation processing by the voice call processing circuit constituted by a single processor. The manufacturing cost can be reduced by reducing the number of parts as compared with the conventional example in which each processing is performed in combination.
[Brief description of the drawings]
[Figure 1]Reference example of the present invention1 is a system configuration diagram of an intercom system including one intercom transfer apparatus.
FIG. 2 is a block diagram of a call processing unit in the same as above.
FIG. 3 is a flowchart for explaining the operation of the call processing unit.
[Fig. 4]Reference example of the present invention2 is a system configuration diagram of FIG.
FIG. 5 is a block diagram of a call processing unit in the same as above.
FIG. 6 is an embodiment.1It is a block diagram of the telephone call processing part in FIG.
FIG. 7 is an operation explanatory diagram of the above.
FIG. 8 is a block diagram of a call processing unit when the above is configured as an interphone master unit.
FIG. 92It is a block diagram of the telephone call processing part in FIG.
FIG. 10 is a block diagram of a call processing unit when the above is configured as an interphone master unit.
FIG. 11 Embodiment3It is a block diagram which shows the principal part.
FIG. 12 is an embodiment.4It is a block diagram which shows the principal part.
FIG. 13 is a block diagram of a conventional interphone master unit and interphone slave unit.
[Explanation of symbols]
  M Intercom transfer device
  3 Telephone interface part
  4 Call processor
  5 1st 2-wire-4 wire conversion part
  6 Second 2-wire-4 wire converter
  7 Control unit
  A Intercom master unit
  B Intercom handset
  C Outside call terminal
  N Public telephone network

Claims (4)

Used in an intercom system that has an intercom handset installed outside the home and an interphone base unit installed in the home and connected to the intercom handset via a telephone line. A transfer means for transferring call voice with the handset, a call processing means for performing a call processing for making a two-way call between the intercom handset and the outside call terminal, and between the call line and the call processing means. And a second 2-wire / four-wire conversion means provided between the transfer means and the call processing means , wherein the call processing means is a call terminal outside the home. A first echo canceller for canceling an echo generated by acoustic coupling in the second line-to-four-line conversion means, or acoustic coupling in the intercom handset or first two-line- A second echo canceller for canceling echo generated by signal wraparound in the line conversion means, and a speech volume adjustment amplifying means provided on the signal path of the speech signal sandwiched between the first and second echo cancellers; A voice switch that is provided between the first and second echo cancellers and that reduces the loop gain of the closed loop formed by the respective echo paths and suppresses howling. A first loss insertion means for inserting a loss into the signal path of the call signal transmitted to the intercom handset; and a second for inserting a loss into the signal path of the call signal transmitted from the interphone handset to the call terminal outside the home. Loss insertion means, and insertion loss amount control means for controlling the amount of loss inserted from the first and second loss insertion means. The insertion loss amount control means includes a second loss control means. Estimating the first feedback gain in the first feedback path returning from the output point of the insertion means to the input point of the first loss insertion means via the feedback path on the side of the telephone terminal outside the home, and the first loss Estimating a second feedback gain in a second feedback path that feeds back from the output point of the insertion means to the input point of the second loss insertion means via the feedback path on the intercom handset side, and the first and second feedbacks A total loss amount calculation unit that calculates the total amount of loss to be inserted into the closed loop based on the estimated value of the gain, and estimates the call state by monitoring the call signal, and the estimation result and the calculated value of the total loss amount calculation unit And an insertion loss amount distribution processing unit that determines the distribution of each insertion loss amount of the first and second loss insertion means, and the total loss amount calculation unit estimates the first and second feedback gains. Based on the value, calculate the total amount of loss to be inserted into the closed loop and There are two operation modes, a new update mode and a fixed mode in which the total loss is fixed to a predetermined initial value, and the first and second echo cancellers from the start of a call between the intercom handset and the call terminal outside the home The first and second voice switches are operated in the fixed mode during the period until the first and second echo cancellers are sufficiently converged and in the update mode during the period after the first and second echo cancellers are sufficiently converged. Third loss insertion means provided at a stage subsequent to at least one of the second loss insertion means to insert a loss into the signal path, and an input to the voice switch in the signal path provided with the third loss insertion means An instantaneous power estimating means for estimating the instantaneous power of the signal, and a third loss insertion means when the estimated value of the instantaneous power by the instantaneous power estimating means continues for a predetermined time or more and falls below a threshold value. Intercom transfer apparatus characterized by comprising a communications unit and control means for inserting a loss of a predetermined amount from. Used in an intercom system that has an intercom handset installed outside the home and an interphone base unit installed in the home and connected to the intercom handset via a telephone line. A transfer means for transferring call voice with the handset, a call processing means for performing a call processing for making a two-way call between the intercom handset and the outside call terminal, and between the call line and the call processing means. And a second 2-wire / four-wire conversion means provided between the transfer means and the call processing means, wherein the call processing means is a call terminal outside the home. In the first feedback path caused by the signal coupling in the acoustic coupling or in the second two-wire to four-wire converting means, and in the intercom handset or in the first two-wire to four-wire converting means A voice switch that suppresses howling by reducing a loop gain of the closed loop formed by the second feedback path generated by the sneaking of the signal, and the voice switch is a call transmitted from the telephone terminal outside the home to the interphone handset A first loss insertion unit that inserts loss into the signal path of the signal, a second loss insertion unit that inserts loss into the signal path of the call signal transmitted from the intercom handset to the call terminal outside the home , And the first and second feedback gains that are fed back through the second and second feedback paths, respectively, and the total amount of loss to be inserted into the closed loop is calculated based on the estimated values of the first and second feedback gains. An insertion loss amount control unit that determines the distribution of each insertion loss amount of the first and second insertion loss units according to the sum of the call state and loss amount estimated by monitoring the call signal, and included in the call signal Outside A first background noise level estimator for estimating the background noise level on the talk terminal side, a second background noise level estimator for estimating the background noise level on the intercom handset side included in the speech signal, and insertion loss control A first bias mode setting amplifying unit for amplifying a call signal from an out-of-home call terminal monitored by the communication unit to the intercom handset, and an out-of-home call terminal from the intercom handset monitored by the insertion loss amount control unit A second bias mode setting amplifying unit for amplifying a call signal to the first, a first feedback gain estimating unit for estimating a feedback gain of the first feedback path, and a first gain for estimating the feedback gain of the second feedback path. 2, the gains of the first and second bias mode setting amplification units are adjusted according to the first and second background noise levels and the estimated values of the first and second feedback gains. A bias mode control unit, and a bias mode The control unit is in a state where the estimated value of the second background noise level is sufficiently larger than the estimated value of the first background noise level and the estimated value of the first feedback gain is smaller than the predetermined value. Continues for a certain time or more, the gain of the first bias mode setting amplification unit is increased more than the gain of the second bias mode setting amplification unit to set the voice switch to the first bias mode, If the estimated value of the background noise level is sufficiently larger than the estimated value of the second background noise level and the estimated value of the second feedback gain is a value smaller than the predetermined value continues for a certain time or longer. The gain of the second bias mode setting amplification unit is set to be larger than the gain of the first bias mode setting amplification unit to set the voice switch to the second bias mode, and the estimated value of the first background noise level The difference in the estimated value of the second background noise level is large enough Intercom transfer apparatus condition to be have value and sets the neutral mode communications unit by not amplifying the speech signals in the first and second unbalance mode setting amplification unit to be continued for a fixed time or more . 3. The microphone and speaker, and switching connection means for selectively switching and connecting the second 2-wire to 4-wire conversion means to the microphone, speaker and transfer means , according to claim 1 or 2. Interphone transfer device. When an abnormality such as a fire or gas leak is detected by a sensor installed in the house, a voice generation means that generates an alarm message or an alarm sound according to the detected abnormality content and a call processing means are a single intercom transfer apparatus according to any one of claims 1 to 3 comprising the voice call processing circuit formed by the processor.

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